Formwork girt

ABSTRACT

A device for use in construction which includes an elongate member having an upright wall portion with a lateral flange extending from one side thereof and a support portion located on an opposite side of the upright wall for supporting a wall panel and wherein the lateral flange is adapted to at least in part be engaged by a fastener to enhance securement of the wall panel to the device.

FIELD OF THE INVENTION

[0001] The present invention relates generally to a constructional member and relates particularly, though not exclusively, to formwork girt such as that used in building construction. The invention also relates to a method of building construction employing the constructional member.

BACKGROUND OF THE INVENTION

[0002] Small buildings including dwellings, garages and sheds, comprise a horizontal floor slab, a plurality of upright walls in the form of wall cladding and a roof. Horizontal rail elements, known as girts are usually provided about the perimeter of the floor slab to support the wall cladding. Girts are generally cold roll-formed from light gauge steel strips and are usually in the form of A-, C- or Z-shaped purlins. Girts are generally positioned along the upper edge margin of the slab and fastened to the columns by means of bolts or other relatively heavy duty fasteners.

[0003] The walls are usually fastened to girts by means of fasteners, such as for example, rivets or self tapping screws, and the roof is then fastened to frame members and the upper ends of the walls. The structure is then braced. The mode of attachment between the building members enables them to be rapidly assembled on site by relatively unskilled labour. However, this in itself facilitates problems of misalignment and torsional and other stresses within and between the building elements. Traditionally, construction of the floor slab requires the erection and dismantling of temporary formwork and generally produces a floor slab having visually obtrusive, unsightly side walls. Further a major portion of the delay between the commencement of the formwork and the completion of the building can be attributed to the hardening or setting stage of the concrete slab.

[0004] The applicant's Australian patent No. 714693 describes formwork girt cold roll-formed from relatively light gauge strip steel. The formwork girt includes an elongate web having a protruding rib, and a pair of edge flanges projecting from an opposite side of the web. Importantly, the rib defines a ledge upon which wall cladding is supported and fastened to an upper portion of the web. The upper edge flange is bent back toward the web to form a partly enclosed space or cavity which enables an end of the wall cladding fastener to protrude unhindered into the cavity.

DISCLOSURE OF THE INVENTION

[0005] According to one aspect of the present invention there is provided a constructional member comprising:

[0006] an elongate web being adapted to provide mounting for a wall panel which is secured thereto via a fastener; and

[0007] a flange connected to and protruding from the web, the flange being configured to at least in part be engaged by the fastener to enhance securement of the wall panel to the constructional member.

[0008] According to another aspect of the present invention there is provided a method of building construction comprising the steps of:

[0009] providing a constructional member including an elongate web to which a protruding flange is connected;

[0010] laying the constructional member to provide peripheral formwork for a floor slab; and

[0011] mounting a wall panel to the constructional member via one or more fasteners each being arranged to engage the flange to enhance securement of the wall panel to the constructional member.

[0012] Generally the method also comprises pouring the floor slab in concrete either prior to or after fastening of the wall panel to the constructional member.

[0013] Generally the protruding flange is formed integral with the web.

[0014] Typically the flange is elongate and protrudes substantially orthogonally from the web. More typically the fastener is aligned with the flange on securement of the wall panel to the constructional member.

[0015] Preferably the web of the constructional member includes a rib protruding in an opposite direction to the flange and having a ledge on which the wall panel rests.

[0016] Typically the flange is one of a pair of elongate flanges being oriented parallel to and laterally spaced from one another.

[0017] Preferably the pair of spaced flanges includes a pair of respective holes being aligned for receipt of a rod or peg for anchoring of the constructional member.

[0018] Typically the orthogonal flange includes a free edge portion directed substantially parallel to the web to define a channel section. More typically the channel section is adapted to receive a joiner element which facilitates butt jointing with an adjoining constructional member.

[0019] Preferably the constructional member is a girt. More preferably the girt is a formwork girt.

[0020] Typically the constructional member is formed of a plastics material. More typically the constructional member is extruded from a foamed plastic such as foamed polyvinylchloride (PVC).

[0021] According to another aspect of the present invention there is provided a device for use in construction comprising an elongate member having an upright wall portion with a lateral flange extending from one side thereof and a support portion located on an opposite side of the upright wall for supporting a wall panel and wherein the lateral flange is adapted to at least in part be engaged by a fastener to enhance securement of the wall panel to the device.

[0022] Preferably the support comprises an elongate rib.

[0023] The support preferably includes a ledge which is adapted to receive a base portion of a wall panel.

[0024] The support preferably has an inclined lower wall portion located underneath the ledge.

[0025] The elongate member preferably includes a lower flange which is adapted to act as a foot for supporting the device on a surface.

[0026] The lower flange is preferably substantially identical to the lateral flange.

[0027] The lower flange is preferably aligned on the same side of the upright wall portion as the lateral flange.

[0028] The lateral flange preferably includes a distal end with an upstanding wall such as a lip or rim.

[0029] The lower flange preferably has a distal end with an upstanding wall.

[0030] The upstanding wall may be continuous or segmented.

[0031] Preferably the device includes one or more lateral flanges.

[0032] Preferably the or each flange forms a channel with the upright wall portion, which channel is adapted to receive a connecting member whereby adjacent devices can be connected together.

[0033] Preferably adjacent devices are adapted to be connected together by a key member which is adapted to fit into the channel of one of the devices and connect into the channel of the other of the devices.

[0034] Preferably the distal wall and opposite section of the upright wall portion include detent means for preventing the key from being lifted out of the channel.

[0035] The detent portions preferably extend along the inner faces of the upright wall of the distal end and the opposite section of the upright wall portion.

[0036] According to another embodiment like devices are adapted to be connected together by connection means which include anyone of the following:

[0037] coupling male and female portions;

[0038] interconnecting members which connect with end portions of each end of the devices;

[0039] clips and fasteners.

[0040] It is preferred that two devices can be connected together by a bonding substance such as glue once they have been aligned adjacent each other using one of the previously mentioned connection methods.

[0041] According to another embodiment of the present invention the lateral flange decreases in width from the upright wall portion towards the distal end thereof, to assist with locating of a fastening member therein.

[0042] According to a further embodiment of the present invention the upright wall includes marking means for identifying the location of the lateral flange on the opposite side wall of the upright wall portion.

[0043] The marking means may be one or more dots or lines slightly above and below the level of the lateral flange.

[0044] The upright wall of the distal end of the lateral flange may include an inwardly directed portion which is wider at its top end.

[0045] The elongate wall member may include a retention means to assist with retention of the device in concrete when in use.

[0046] The or each flange (lateral, lower etc), may include surface formations to assist with retention of the flange with concrete.

[0047] It is preferred that flanges at upper and lower ends of the elongate member have distal ends which curve downwardly and upwardly respectively.

[0048] According to another embodiment of the present invention at least one of the flanges is provided with a series of vertical holes to allow a fastening member to be located therethrough.

[0049] Preferably the device is formed from a plastics material.

[0050] According to a preferred embodiment the device is used as formwork girt.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to achieve a better understanding of the nature of the present invention a preferred embodiment of a constructional member and a method of building construction will now be described, by way of example only, with reference to the accompanying drawings in which:

[0052]FIG. 1 is a sectional view of a constructional member employed as formwork together with a wall panel;

[0053]FIG. 2 is an end view of the constructional member of FIG. 1; and

[0054]FIG. 3 is a schematic in end elevation of an alternative constructional member.

DETAILED DESCRIPTION OF THE DRAWINGS

[0055] As shown in FIG. 1 there is a constructional member in the form of a formwork girt 10 employed in building construction with a wall panel 12 and a floor slab such as the concrete floor slab 14.

[0056] The formwork girt 10 generally comprises an elongate web 16 and a flange 18 connected to and protruding orthogonally from the web 16. The web 16 includes an elongate rib 20 which protrudes in an opposite direction to the flange 18 and provides a ledge 22 on which the wall panel 12 rests. The formwork girt 10 includes a lower flange 24 arranged parallel to and laterally spaced from the upper flange 18. The upper and lower flanges 18 and 24 each include a free edge portion which is directed upwardly and generally parallel to the web 16 so as to define a channel section such as 26. The upper flange 18 is located above the ledge 22 on an opposite side of the web 16 whereas as the lower flange 24 is provided at a lower edge of the web 16 below the rib 20. The pair of flanges 18 and 24 include a pair of respective holes (not shown) which are vertically aligned. The holes are designed to receive a rod or peg 28 for anchoring of the formwork girt 10. The formwork girt 10 is prevented from sliding up or down the peg 28 by means of a wedge element 30 which locates between the web 16 and the peg 28 beneath the upper flange 18.

[0057] The wall panel or cladding 12 of this embodiment is mounted or secured to the formwork girt 10 via fasteners such as the screw fastener 32. The screw fastener 32 is aligned with and engages the upper flange 18 so as to enhance securement of the wall panel 12 to the formwork girt 10. The applicant has conducted comparative tests with the formwork girt of Australian patent No. 714693 and has surprisingly found that the formwork girt 10 of this embodiment of the present invention has a tear-out value of several times greater. It is understood that in this example the tear-out value is enhanced by the fact that the flange 18 does not displace under loading of the wall panel 28. The embedding of the flange 18 in the concrete slab 14 resists displacement and the upwardly directed edge portion of the flange 18 “locks” the formwork girt 10 in place.

[0058] The formwork girt 10 of the described embodiment is formed from a foamed polyvinylchloride (PVC) plastic. The formwork girt is preferably extruded from a plastics material although any other suitable material, such as coated steel, may be used. The plastics formwork girt is particularly suited insofar as the wall panel 12 may be secured to the formwork girt 10 with minimum ease whilst providing advanced securement of the wall panel 12 compared to traditional techniques.

[0059] The formwork girt 10 of FIG. 2 is identical to that of the preceding embodiment but with joiner elements 34 and 36 being shown. The joiner elements 34 and 36 of this example are plastic strips used to facilitate butt jointing of adjoining constructional members in the form of formwork girts such as 10. The channels such as 26 of the upper and lower flanges 34 and 36 include inwardly directed protrusions such as 38 and 40 which permit press fitting of the plastic strip which facilitates alignment and butt jointing of adjacent formwork girts such as 10.

[0060] The formwork girt 10 of this embodiment also includes an elongate ridge 42 formed at an upper ridge of the web 16. The ridge 42 serves to provide an upper platform for the floor slab 14 and increases the rigidity of the web 16. The ridge 42 tapers inwardly as it approaches the web 16 and together with the upper and lower flanges 18 and 24 promotes retention of the formwork girt 10 with the floor slab 14.

[0061]FIG. 3 is a schematic of an alternative embodiment of the formwork girt 100. For ease of reference and in order to avoid repetition like components of this alternative girt 100 compared to the preceding girt 10 will be designated with an additional “0”. For example, the uppermost flange has been designated as 180. The alternative formwork girt 100 is cold roll-formed from strip steel. Otherwise, the alternative formwork girt is in cross-sectional profile substantially identical to the preceding girt 10. Importantly, the uppermost flange 180 is formed by a pair of opposing flange walls 181 and 183, respectively. The opposing flange walls 181 and 183 are both lightly corrugated and spaced a distance apart which is suitable for engagement with a typical fastener. This engagement of the fastener with the upper flange 180 is enhanced by embedding of the flange 180 in a concrete slab (not shown) which “locks” the formwork girt 100 in place.

[0062] The general steps involved in a method of building construction utilising the formwork girt 10 of the preceding aspect of the invention will now be outlined:

[0063] the formwork girt 10 is laid about a prepared site on which a concrete slab such as a floor slab 14 is to be poured;

[0064] the formwork girt 10 is anchored to the ground via one or more of the pegs 28;

[0065] the formwork girt 10 is oriented in its preferred horizontal plane possibly with a slight water run-off and locked in position with one or more of the wedges 30;

[0066] adjacent formwork girts such as 10 are adjoined with insertion of the strips 34 and 36 and alignment of the abutting girts;

[0067] the concrete floor slab 14 is poured;

[0068] the wall panels such as 12 are erected about the formwork girt such as 10 resting on the ledge 22 and secured to the girt 10 via fasteners such as 32 which importantly penetrate the upper flange 18 for enhanced securement.

[0069] The building construction is then completed using otherwise traditional techniques such as those acknowledged in the admitted art. It should also be appreciated that the steps outlined above may be varied, for example the walls may be erected prior to pouring of the floor slab. The wall panels such as 12 are screw fastened to the formwork girt 10 using a screw gun which includes an extractor having a cone-shaped head (not shown). The uppermost flange 18 is positioned relative to the ledge 22 whereby the extractor when positioned on the ledge 22 automatically aligns the screw fastener such as 32 with the uppermost flange 18. If an alternative extractor or screw bit of a different diameter is utilised it may be aligned with the uppermost flange 18 by location of a spacer on or adjacent to the ledge 22.

[0070] Now that a preferred embodiment of the present invention has been described in some detail it will be apparent to those skilled in the art that the constructional member and method of building construction of at least the preferred embodiments have the following advantages:

[0071] the constructional member enhances securement of the wall panel;

[0072] the constructional member is inexpensive to manufacture to relatively tight tolerances;

[0073] the constructional member at least in its preferred form can be assembled in a modular fashion.

[0074] the constructional member provides a vermin-proof barrier;

[0075] the constructional member facilitates relatively quick setup time and no formwork is required; and

[0076] the constructional member functions as a load bearing member and lighter framework can be used.

[0077] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. For example, the constructional member need not include the rib and ledge as described but rather may involve mounting of a wall panel to a substantially flat web. The constructional member may include a single flange only which is engaged by the fasteners of the wall panel.

[0078] All such variations and modifications are to be considered within the scope of the present invention the nature of which is to be determined from the foregoing description.

[0079] It is to be understood that a reference herein to a prior art document does not constitute an admission that the document forms part of the common general knowledge in the art in Australia or in any other country. 

The claims defining the invention are as follows:
 1. A device for use in construction comprising an elongate member having an upright wall portion with a lateral flange extending from one side thereof and a support portion located on an opposite side of the upright wall for supporting a wall panel and wherein the lateral flange is adapted to at least in part be engaged by a fastener to enhance securement of the wall panel to the device.
 2. The device as claimed in claim 1 wherein the support portion comprises an elongate rib.
 3. The device as claimed in claim 1 or 2 wherein the support portion includes a ledge which is adapted to receive a base portion of the wall panel.
 4. A device as claimed in claim 3 wherein the support portion has an inclined lower wall portion located under the ledge.
 5. The device as claimed in claim 1 or 4 wherein the elongate member includes a lower flange which acts as a footing for supporting the device on a surface.
 6. The device as claimed in claim 5 wherein the lower flange is substantially identical to the lateral flange.
 7. The device as claimed in claim 6 wherein the lower flange is aligned on the same side of the upright wall portion as the lateral flange.
 8. The device as claimed in claim 7 wherein the lateral flange includes a distal end with an upstanding wall.
 9. The device as claimed in claim 8 wherein the lower flange has a distal end with an upstanding wall.
 10. The device as claimed in claim 9 wherein the lateral flange and the lower flange form a channel with the upright wall portion, which channel is adapted to receive a connecting member whereby adjacent devices can be connected together.
 11. The device as claimed in claim 10 wherein the connecting member comprises a key member slidable within the or each channel.
 12. The device as claimed in claim 11 including a detent means for preventing the connecting member from being lifted out of the channel.
 13. A constructional member comprising: an elongate web being adapted to provide mounting for a wall panel which is secured thereto via a fastener; and a flange connected to and protruding from the web, the flange being configured to at least in part be engaged by the fastener to enhance securement of the wall panel to the constructional member.
 14. A constructional member as defined in claim 13 wherein the flange is elongate and protrudes substantially orthogonally from the web and the fastener is aligned with the flange on securement of the wall panel to the constructional member.
 15. A constructional member as defined in claim 13 or 14 wherein the web of the constructional member includes a rib protruding in an opposite direction to the flange and having a ledge on which the wall panel rests.
 16. A constructional member as defined in claim 13 wherein the orthogonal flange includes a free edge portion directed substantially parallel to the-web to define a channel section which is adapted to receive a joiner element which facilitate butt jointing with an adjoining constructional member.
 17. A method of building construction comprising the steps of: providing a constructional member including an elongate web to which a protruding flange is connected; laying the constructional member to provide peripheral formwork for a floor slab; and mounting a wall panel to the constructional member via one or more fasteners each being arranged to engage the flange to enhance securement of the wall panel to the constructional member. 